(1) Field of the Invention
The present invention relates to a user interface device and a personal digital assistant (PDA) which can convey information to a user according to a tactile and visual mode.
(2) Description of the Related Art
In the past, for example, an information display/input device, in which a so-called touch panel is arranged on a display of a liquid crystal panel, displays an image of a virtual key on a display screen and makes it possible to input or select the information allocated to the virtual key, by a user touching the top of the touch panel area corresponding to the display position of the virtual key with a fingertip or a nib of a stylus pen, etc.
Document 1 (JP-2004-157933 A, FIG. 1 and FIG. 9) discloses a concavo-convex formation device which includes: plural displacement elements possessing a displacement unit arranged on a transparent substrate, and a displacement power generator operable to displace the displacement unit in a separating direction from the substrate correspondingly to a control signal; a transparent film layer provided in the vicinity of these displacement elements and operable to deform a contact portion to convex when the displacement unit receives a displacement power at the contact portion concerned; and a control means operable to output a control signal to each of the displacement elements individually. In the concavo-convex formation device, a transparent substrate and a film layer are laminated with a display device to form structure of a panel, over the surface of which a touch detection means is provided to detect contact. In Document 1, a user is informed of an appointed display position (for example, a virtual key position) to be touched at the time of a touch panel operation, by displacing to a shape of convex the transparent film layer of the concavo-convex formation device.